1. Field of the Invention
The present invention relates to a method and apparatus for calibrating a biometric marker over time for the purpose of authenticating the person. More specifically, the present invention relates to methods and apparatus for calibrating an internal biometric marker that is substantially unique to a person in order to permit the person to activate a device, participate in a transaction, or identify him or herself.
2. The Background Art
The computer industry has recognized a growing need for sophisticated security systems for computer and electronic devices. The security systems prevent unauthorized use and authenticate or identify individuals through electronic means. The biometric authentication industry has developed in response to this need. Biometrics are the measurement of quantifiable biological traits. Certain biological traits, such as the unique characteristics of each person's fingerprint, have been measured and compared and found to be unique or substantially unique for each person. These traits are referred to as biometric markers. The computer and electronics industry is developing identification and authentication means that measure and compare certain biometric markers with the intention of using the markers as biological “keys” or “passwords.”
Biometric markers presently used by the industry for authentication and identification include the use of measurements of unique visible features such as fingerprints, hand and face geometry, and retinal and iris patterns, as well as the measurement of unique behavioral responses such as the recognition of vocal patterns and the analysis of hand movements. The use of each of these biometric markers requires a device to make the biological measurement and process it in electronic form. The device may measure and compare the unique spacing of the features of a person's face or hand and compare the measured value with a value stored in the device's memory. Where the values match, the person is identified or authorized.
Several types of technologies are used in biometric identification of superficial anatomical traits. For example, biometric fingerprint identification systems may require the individual being identified to place their finger on a visual scanner. The scanner reflects light off of the person's finger and records the way the light is reflected off of the ridges that make up the fingerprint. Hand and face identification systems use scanners or cameras to detect the relative anatomical structure and geometry of the person's face or hand. Different technologies are used for biometric authentication using the person's eye. For retinal scans, a person will place their eye close to or upon a retinal scanning device. The scanning device will scan the retina to form an electronic version of the unique blood vessel pattern in the retina. An iris scan records the unique contrasting patterns of a person's iris.
Still other types of technologies are used for biometric identification of behavioral traits. Voice recognition systems generally use a telephone or microphone to record the voice pattern of the user received. Usually the user will repeat a standard phrase, and the device compares the measured voice pattern to a voice pattern stored in the system. Signature authentication is a more sophisticated approach to the universal use of signatures as authentication. Biometric signature verification not only makes a record of the pattern of the contact between the writing utensil and the recording device, but also measures and records speed and pressure applied in the process of writing.
Each of the prior art systems has a number of disadvantages. For example, fingerprint data bases may raise significant privacy issues for those whose information is entered in the system. Hand and facial geometry recognition systems may require large scanners and/or expensive cameras. Voice recognition devices have problems screening out background noise. Signature recognition devices are subject to variations in the behavior of the individual. Retinal devices may require users to place their eye close to or on a scanning device, exposing the user to potential infection.
Another disadvantage of the prior art to biometric authentication is the limited number of biometric markers that are unique to each individual and that are practical for implementing in computer and electronic devices. Because the biometric patterns used in the prior art to authenticate a person are potentially completely unique to each person, the differences that distinguish one person from another person may be subtle. It may require a high degree of electronic sophistication to read and differentiate between the various unique aspects of the biometric marker. If the biometric marker is used to identify an individual from a large group of individuals, the computer memory storage and processing capability may also have to be sophisticated, and therefore, may be expensive.
Another disadvantage of prior art is that with relatively few truly unique biometric markers, it is likely that those markers will be used in multiple devices. Use in multiple devices of the limited number of unique markers increases the risk of harm to the authorized user in the event an unauthorized person is able to forge or otherwise counterfeit one of the unique biometric markers. This is the same problem that exists when a person chooses the same alpha-numeric password for all his accounts or electronic devices. Markers that are difficult to forge, and a greater number of them, are needed to reduce the potential harm to the authorized user from forged our counterfeit marks.
U.S. Pat. No. 4,537,484 to Fowler et al. discloses a fingerprint imaging apparatus for use in an identity verification system. The system uses light, which is reflected off the finger through a system of mirrors to a linear photo diode ray. The fingers rotated mechanically in order to scan the entire fingerprint.
U.S. Pat. No. 4,544,267 to Shore discloses an identification device that uses a beam of collimated light to scan the fingerprint. The light beam is then imaged onto a linear ray of photo-responsive devices. The information is processed to provide a set of signals containing fingerprint information.
U.S. Pat. No. 4,699,149 to Rice discloses a device for detecting the position of subcutaneous blood vessels such as by using the reflection of incident radiation off of a user's skin. The measured pattern is then compared with a previously determined pattern to verify the identity of the user.
U.S. Pat. No. 4,728,186 to Eguchi et al. discloses another method for detecting data an uneven surface such as a finger, namely a fingerprint, using a light source illuminating the uneven surface through a transparent plate.
U.S. Pat. No. 4,784,484 to Jensen discloses an apparatus for automatic scanning of a fingerprint using an optical scanner. The user slides his finger across a scanning surface and an optical scanning system generates an electrical signal as a function of the movement of the finger across the optical scanning surface.
U.S. Pat. No. 5,073,950 to Colbert et al. discloses a method and apparatus for authenticating and verifying the identity of an individual based on the profile of a hand print using to an optical scanner.
U.S. Pat. No. 5,077,803 to Kito et al. discloses a fingerprint collating system employing a biological detecting system.
U.S. Pat. No. 5,088,817 discloses an apparatus for detecting and identifying a biological object by projecting a light beam onto the object and detecting the reflective light using an optical detector. The change in the wave length characteristics of the light beam can be compared to a previously determined pattern.
U.S. Pat. No. 5,230,025 discloses a system for generating data characteristics of a rolled skin print using an optical device that can convert reflective light beams into an electronic signal and generate digital data representative of the image of the skin print.
U.S. Pat. No. 5,335,288 to Faulkner discloses a biometric measuring apparatus that uses silhouette and light images to measure a person's hand features. The features are converted to electronic data and stored and later compared for identification purposes.
Some biometric authentication systems combine biometric measurements with conditions behavior such as signature writing styles and voice patterns or intonations. For example, U.S. Pat. No. 5,103,486 to Grippey discloses a signature verification system utilizing a handheld writing implement that produces data regarding a person's fingerprint pattern and their hand written signature.
Other biometric authentication systems include means for verifying physiological activity. These means for verifying physiological activity are primarily to prevent an unauthorized person from using dead tissues as a means for circumventing the authentication process. For example, U.S. Pat. No. 5,719,950 to Osten et al. discloses a personal biometric authentication system wherein inherently specific biometric parameters are measured and recognized and at least one non-specific biometric parameter is recognized and compared with physiological norms. Likewise, U.S. Pat. No. 5,727,439 to Lapsley et al. discloses an antifraud biometric scanner that determines whether blood flow is taking place in the object being scanned and whether such blood flow is consistent with that of a living human.
One of the difficulties arising from the use of biometric markers for authentication is that the changes that occur in a person's features or physiology over time can alter the measurement of those features and physiology and result in a false negative identification. For example, if a person's facial features are used as a means of biometric identification, and through age or accident the person's features are changed, biometric identification based upon the person's features prior to the change may not be possible. In order to take into account such changes, some biometric authentication systems that rely upon superficial structure or behavioral response have proposed methods for calibrating the authenticating biometric over time.
U.S. Pat. No. 5,892,824 to Beatson et al. discloses a biometric template updating process for signature verification, in which an original signature template is modified based on a feature comparison process used in authentication that results in an updated authenticating signature template. U.S. Pat. No. 6,111,517 to Atick et al. in which a face recognition biometric device periodically updates the image memory used to authenticate the individual to reflect changes in the appearance of the individual.
The calibration over time of internal physiological and histological markers is complicated by the aging that takes place in the body. The aging process affects the organ systems in the body, which may result in an alteration of the physiological or histological markers. For example, in the integumentary system, as the body ages a degenerative change occurs in collagenous and elastic fibers within the dermis, there is decreased production of pigment in the skin and hair follicles and reduced activity of sweat and sebaceous glands. the body's skin tends to become thinner, more wrinkled and dry with pigmentation spots and the hair becomes gray and ultimately white. Within the skeletal system there is a degenerative loss of matrix, a deterioration of the joints and articulations, bones generally become thinner and more brittle.
Within the muscular system there is a loss of skeletal muscle mass, muscular strength, and motor response. In the circulatory system, the cardiac muscle degenerates and there is decreased diameters of the lumina of the arteries and arterioles, decreased cardiac output, increased resistance to blood flow, and increased blood pressure. With the respiratory system, aging brings on a degenerative loss of elastic fibers in the lungs, a reduced number of functional alveoli, and a reduced vital capacity. Other systems within the body suffer similar degernative effects with aging.
Unlike the calibration issues addressed in superficial biometric markers or behavioral markers, internal physiological and histological markers undergo different kinds of changes. These changes are for the most part invisible and unlike superficial biometric markers, may give no obvious indicia of the change. Likewise, many of the changes in the body systems are largely involuntary responses. These physiological markers do not provide the individual being authenticated an opportunity to try to compensate for whatever changes may occur over time. The changes which occur in internal biometric markers are highly individualized in terms of their timing and degree of change, and therefore may not be compensated for by calibration methods not tailored to the actual changes occurring but are rather predetermined by some other method. Lastly, because internal biometric markers are often combined to form a “compound” biometric marker comprised of a number of physiological and histological features, calibration can be more complicated. In the preferred embodiments of the related applications, multiple features of a physiological event are measured and a select number of the features are used depending on the consistency and distinctiveness of the features. Thus, the features used to authenticate and identify one individual using the system will be different than those features used to identify another individual. With such a system, it is important that the calibration techniques take into account the unique nature of the internal biometric marker.
It would therefore be advantageous to provide a method and software for calibrating internal biometric markers and specifically calibrating internal physiological and histological biometric markers over time.
It would also be advantageous to provide a method and apparatus for biometric authentication and activation that does not exclusively rely upon the measurement of superficial anatomical structure and/or behavioral responses and can be calibrated over time. It would also be advantageous to provide a biometric authentication system that is relatively inexpensive and portable. It would be a further advantage to provide a biometric authentication system that can use but does not require the use of truly unique biometric markers where such markers can be calibrated over time. It would also be advantageous to provide a method and apparatus for biometric authentication that can use a single technology to measure multiple, varied biometric markers.